In Areopagitica (1643), Milton declared that on his earlier tour to Italy he had “visited the famous Galileo, grown old, a prisoner to the Inquisition, for thinking in astronomy otherwise than the Franciscan and Dominican licensers thought.” In Paradise Lost, Galileo—“the Tuscan Artist”—is the only contemporary of Milton’s referred to by name. By looking at Galileo’s achievements and his writing more closely, Professor Danielson will try to forge fresh insights into the optics and cosmology of Milton’s epic world.